Urban Company - Marbles damaged after cleaning service

my mom had booked a sofa cleanup service on **th oct and the service finished alright. the guy cleaned up the marbles with some chemicals and my mom told him beforehand to not use third party chemicals for the cleanup and the guy replied that it was okay and they use it regularly. next morning all the cleaned marbles started turning black and there were dark marks visible. she tried cleaning by moping repeatedly but couldn't get it cleaned up. she tried everything but it didn't make any difference. i request you to kindly provide a valuable solution to this huge mess created by your worker. i even tried calling the cleaning guy but for * days he kept dodging the calls by saying he will visit but didn't. it's been almost a week now and we're helpless at this point